The secessionist movement in the Mizo Hills (now Mizoram) was driven by several factors:
1. Neglect by the Government: The Mizo people felt neglected by the Indian government, especially regarding the development of the region and their demands for autonomy.
2. Economic Grievances: Poverty, underdevelopment, and the lack of basic infrastructure contributed to resentment and led to calls for independence from India.
3. Insurgency and Armed Conflict: The Mizo National Front (MNF) led an armed rebellion against the Indian government from 1966 to 1986. The movement demanded the creation of an independent Mizo nation, but it was eventually quelled by the Indian military.
4. Peace Accord and Statehood: In 1986, after years of conflict, the Mizo Peace Accord was signed, which led to the creation of Mizoram as a full-fledged state of India.
Thus, the correct answer is (a).